Message: Invalid params: unknown variant `single`, expected one of `processed`, `confirmed`, `finalized

Question

I'm totally new to solana so I'm following the 2023 bootcamp. Episode 1 has a repo you follow with the devrel, which starts with quest 1. He runs it fine in the video but I've encountered several problems. I am a newb mostly so I'm not exactly sure what's going on. First is the warning I would keep getting from getMinimumBalanceForRentExemption. I tried hard coded values similar to what I saw in the video but the error after still gets thrown. The actual error is:

throw new SendTransactionError({

            ^
SendTransactionError: Simulation failed. 
Message: Invalid params: unknown variant `single`, expected one of `processed`, `confirmed`, `finalized`.. 

Catch the `SendTransactionError` and call `getLogs()` on it for full details.

I can't find anything specific to this error, does anyone have any context? I think every quest in the episode uses the account that this TX is supposed to create so I can't continue working along the video

Here is the code from the file I'm trying to run:

// generate a new, random address to create on chain
  const keypair = Keypair.generate();

  console.log("New keypair generated:", keypair.publicKey.toBase58());

  // on-chain space to allocated (in number of bytes)
  const space = 0;

  const lamports = await connection.getMinimumBalanceForRentExemption(space);
  

  console.log("Total lamports:", lamports);

  // create this simple instruction using web3.js helper function
  const createAccountIx = SystemProgram.createAccount({
    // `fromPubkey` - this account will need to sign the transaction
    fromPubkey: payer.publicKey,

    // `newAccountPubkey` - the account address to create on chain
    newAccountPubkey: keypair.publicKey,

    // lamports to store in this account
    lamports,

    // total space to allocate
    space,

    // the owning program for this account
    programId: SystemProgram.programId,
  });

  // get the latest recent blockhash
  let recentBlockhash = await connection.getLatestBlockhash().then(res => res.blockhash);

  // create a message (v0)
  const message = new TransactionMessage({
    payerKey: payer.publicKey,
    recentBlockhash,
    instructions: [createAccountIx],
  }).compileToV0Message();

  // create a versioned transaction using the message
  const tx = new VersionedTransaction(message);

  tx.sign([payer, keypair]);

  console.log("tx after signing:", tx);

  // actually send the transaction
  try{
    const sig = await connection.sendTransaction(tx);
    console.log("Transaction completed.");
    console.log(explorerURL({ txSignature: sig }));
    
  }
  catch (error: any) {

    console.error("Transaction FAILED", error);
    if (error.logs) {
      console.error("Transaction logs: ", error.logs)
    }
    }

Answer 1

After doing some digging I found that sendTransaction does not handle versioned messages well. I had to first serialize my transaction, then specify the preflightCommitment since it kept defaulting to "single" when it should have defaulted to "finalized". I then used sendRawTransaction instead and it worked.